I both agree and disagree.
AMD have got it right releasing their top-end card first. They've claimed the single GPU performance crown, they've given themselves the opportunity to charge a premium price for their product, and those wanting the ultimate (right now) have to choose AMD.
However, nVidia releasing a mid range part first was probably (certainly?) not in the original plan, and to me it seems like a reaction to how well Tahiti performs, and an attempt to retain market share in the mid-high range (aka against 7950, NOT 7970) where - let's face it - the volumes are substantially higher. The high end cards (single and multi-GPU solutions) are only an exercise in "willy waving", and while nVidia are doubtless gutted to be behind AMD in performance it has little real impact on the overall company performance.
If the GK104 based card performs as well as, or slightly better than, the GTX 580 that will be a significant advantage for nVidia. It's generally believed that nVidia have two higher-end parts in the pipeline, GK110 and GK112, and if GK104 performs as well as hoped this leaves us to expect trully staggering things from the high-end parts that will dislodge 7970's performance crown with a huge thump.
7970 does beat GTX 580 sometimes significantly, sometimes less so, but it really only begins to shine out when clocked way above the standard (which is does phenomenally well, I'm sure all will agree). If GK104 is equivalent or slightly better than GTX 580 then the gap to 7970 isn't huge, and who's to say how well GK104 will clock. Maybe that will be a monster as well?
GK104 is definitely intended to compete with 7950, but if it ends up getting close to 7970 performance then AMD will really struggle against GK110/112.